Separation of minerals and other substances



Nov 19, 4 T. M. DAvlDoN 1,736,111

SEPARATION OF MINERALS AND OTHER SUBSTANCES Filed Sept. 14, 1926 5 Sheets-Sheet 1 Inventor Attorney.

Nov. 19, 1929. h T. M. DAVIDSON L7S6,fl1

SEPARATION OF MINERALS AND OTHER SUBSTANCES File' d Sept. 14; 1926 s'she ts-s'heet 2 Inventor Z -JM y All 5 W .dttorney.

Nov. 19,1929. IT. M. DAVIDSON SEPARATION OF MINERALS AND OTHER SUBSTANCES Fnedse t. 14, 1925 5 Sheets-Sheet 5 Inventor 7. 1a.

by A. s. aw.

Attorney;

Nov. 19, 1929.

T. M. DAVIDSON 1,736,111

SEPARATION MINERALS AND OTHER SUBSTANCES Filed Sept. 14, 1926 5 sheets shet 4 Nov. 19, 1929.

'r. M. DAVIDSON SEPARATION .OF MINERALS AND OTHER SUBSTANCES 5 Sheets-She et 5 Filed Sept. 14, 1926 I Inventor by w- 2 20,34

Patented Nov. 19, 1929 UNIT -u STATE-S; PATE roF'FicE THOMAS MALcoLiir nAvInsoNfor HATCH END, MIDDLESEX, ENGLAND SEEARATTON or MINERALSAND OTHER salesman-ens" Application filed Septe'inberf 14; 192e, s'eriarno; 135,454,211141' in Great Britain se temberai, i925,

This invention relates to the washing and separation of minerals and other substances, whereby separation is effected according to the relative specific gravities' of the mineral and the gang'ue, dirt or foreign matter associated with it.v L Y i 7 The invention has special utility in the washing and separation of coal for'the reduction of its content of ash by'washi-ng, and for 10 the separation of the heavier foreign-bodies commonly associated with it, such as 'pyrites, shale, sand and stone, and the invention has among its objects to effect substantially complete separation of the mineral inja simple operation that does not involve the useof an extensive or expensive apparatus; a r

The invention relates to that type of method or apparatus for the separation or washing of minerals andother substances, in

- .i which the reduced or finely divided substance under treatment is fed to an endless conveyor .Whose upper surface 1S lI1Cl'lI1Cl','aI1( 1 has imparted to it a forward and upward move ment lnthe' direct on of its lnclination, as V 2 well as a transversereciprocation, whereby the lighter. particles are discharged at the lower end of the inclined endless conveyor, while the heavier particles are discharged atthe upper end thereof.

According to the invention, the timely divided material to be separated is first fed to an inclined surface or-tray which is also subject to vibration or trans-verse reciprocation, whereby the finely divided material, in its or tray, is more or less separated before deposit upon the separating conveyor, and the heavier particles are discharged fromthe inclined surface or tray onto the conveyor at 4 a position immediately beneath the lower end or other position of discharge, while the lighter particles are deposited upon the separatingconveyor in positions beyond;

A small spray of water or the like may be applied at the top of the upper end of the inclined endless conveyor to further aid-in complete separation of any light particles from the heavier particles that pass upwardly on the conveyor,'and the main part of the v inclined surface or tray, as well as the sepin Figurel.

downward course along the inclined surface is a planview-corresponding to arating conveyor beneath it, are submerge-:1 i

in water} The inclined surface or tray advantageously provided at its lower end with a transverse wall in the lower part of which a slot orthe. like is provided as an outlet for the heavier particles that, in their downward course under the vi bration or reciprocation imparted to the inclined surface or tray,

accumulate more or less at thebottom ofthe f surface or tray, and.

pass off the inclined surface or trayiover the .v

upper edge of the pass through the slo part of the endwall, jandthus'are deposited transverse wall and are deposited on the conveyor in position int-- m'ediately beyond,- while the" heavier particles t or the like at} the lower in position on theconveyor. immediately beneath the lower end or tray.

The invention co method and-apparatus hereinafter described. I

of the inclined surface mprises' the features of The invention-is hereinafter described with arating apparatus tion.

" Figure l -is a diagram mpanying' diagrammatic according to the; invenillustrating the arrangernent of the separating elements shown Figure. 2' Figure 1.:

Fig'uref3e is a cross sectional responding to Figure 1. k I

Figure 4 is a longitudinal sectional view u on an enlarged scale of the upper roller of 7 view corone of the endless belt conveyors andshows also the frame effecting: the reciprocation of the rollers and the eccentric therefor;

provided atone extr Figure i? is a detail plan view of the sleeve emity of the tie-bar.

if', Fig'ure 5 is a detail sectionalviewon the same scale asFigure ivof the mounting for the lower roller. Figure 6 is a secti (final View on an enlarged ional elevationiof a sep- 1 V scale of the upper roller taken through a bearing thereof.

Figure"? is a similar view of the lower roller, and

I Figure 8 is a view in sectional elevation of a modification. I

In carrying the invention into effect accordingto' one construction and with'refer- I ence to Figures 1 to 7 of the accompanying ,theupper rollers of the two conveyors being mounted in juxtaposed' positions. In each case the shaft 6 of the upper roller is rotatably supported at each end in a bearin'g 9 carried by an angle bracket g mounted on the vertical upper side wall of the tank. Lonitudinal movement of the shaft isprevented by means of collars e 7 V The shaft f'ofhe lower roller 03 is'supportedand advantageously fixed at each end in a bearingblock' it having a groove formed in each of the upper and lower surfaces, transversely to theaxis, for engagement with cor- -'respondingly formed slide bars h provided upon anopen frameor fitting k secured to one end of a tie bar '2', the other end of which is pivotally fitted upon the bearing 9. For this purposethe end of the tie bar 2' is formed 7 into an eye or'sleevez' and a second eye or sleeve 71 isformed in a short cranked barfitting riveted: or bolted to the tie bar. The

eyesor sleeves i embracerorresponding bosses 9 upon the bearing. i

For variation of the tension of the belt I), the bearing blocks "h are adjusted along the slide bars 72 by means of screwed spindles h carried by them and passing through lugs it formed upon the frames or fittings h for engagement with adjusting nuts 72, Foradiu'stinent of the inclination of the belt, the tie bars '2' areprovided at the free ends with lugs i towhich are pivoted screwed spindles 2' adapted to slide through supporting brackets a mounted upon the walls of the tank and to be engaged by adjusting nuts 2". By-such means the inclination ofzthe'belt may be varied as desired, for instance, over a range of sav10. I a a The rollers 0, dare adapted to have axial movementupon their respective shafts to a limited degree, and forthis purpose the upper roller 0 is provided with spiders 0 the bore of each ofwhich is somewhat larger in diameter than-the shaft and formed with a number of longitudinal recesses 0 which may be "of rectangular cross-section, extending from the outer'end partlythrough the bore; The shaftis formed with corresponding recesses e and balls 6 are seated part-1y within the recesses c of the spiders and partly in the recesses e of the shaft, thus serving to support the roller upon the shaft, in such. manner that, while the roller is free to move axially to the extent permitted by the length of the recesses, the rotation of the shaft is communicated to the roller. The outer end of the bore of the spider a is closed by an annular cap a screwing into a screw-threaded. part of the bore,

confine the balls 6 within the recesses 0 6 The lower roller 03 is similarly provided with spiders d each havinga bore which is a v V somewhat larger'indiameter than the shaft vf and formed with longitudinal recesses d for the reception'of the balls 7. The shaft f is not recessed to receive the balls, but is formed with a portion f of reduced diameter upon which they may bear, so. that the spider is rotatably carried also move axially. "As in the case of the upper roller, caps d are provided for closing the recesses 03 and for retaining the balls f therein. '7 e 1 The belt, which maybe of rubber or any other suitablematerial, is'made endless and passes direct from one'roller to the other. e

For the transverse reciprocation of the endless belt there is provided, for each conveyor,

upon the shaft, and may a frame comprising two transverse members 3' disposed above and parallel with the axes of the respective upper and lower rollers 0,

cl, and two longitudinal'members d connectc ing the transversemembers. The transverse 1, and longitudinal members ,7, b may be of angle, channel'or other section metal or of wood. The transverse members have secured to them plate members j provided at each end witha downwardly extending arm 7' hav ing at its lower end a sleeve 7'? which is adapted 'to embrace the cylindrical exterior surface of the correspondingcap' 0 or d of the roller; and thus, to support theframe thereon. Gushionin'gsprings are advantageously' interposed between the sleeves i and the spiders c d The arms 7' of the plate member disposed above the" lower roller 0! are provided in two parts which may be adjusted relatively one totlie other to follow the adjustments made in respect of the shaft bear- I ingsfor' variation of the inclination of the belt.- The two parts of the respective arms may be secured togetherin any suitable mannor; as by means'of slots and bolts y' In position immediately above the submerged conveyor 6, an inclined surface or tray 6 is provided, which inclined surface ortray maybe disposed substantially parallel. with the upper part of the conveyor b. The inclined'surface or tray 5 may be provided to have imparted to it a transverse reciprocation. Means may be provided by which the inclination of the inclined surface or tray 6' may be varied independently of 1 75 'so that the cap, when 1n pos1t1on,"serves to s the inclination of the-conveyor '19. Such means may comprise screw-threaded rods 6 to the lower end of which the tray 19 is pivoted, and which pass through fittingsv extending laterally from the longitudinal 6 members I), adjusting nuts 6 being provided The inclinedsurface 'or trayab omay the conveyor, the inclined surface or trap 5 being advantageously disposed so that at its v upper end it risesabove the level ofthe liquid, as'may also the upper end of the-upper 'part of the, oonveyorl b. At the lower endtof the inclined surface or tray 12 a transverse wall 6 is'provided which may bev normally disposed to the'inclined surface or'tray b, in the lower-part of which wall 12 a slot 6 is formed, extending the width of-the tray, the

slot 6 being so disposed that the material lying at the bottom of the lower end 'of the tray 6 readily falls through the slot 6 and downwards onto the conveyor b" beneath. The lower end of the conveyor Z) extends beyond the lower end of the inclined surface or'tray b and a transverse apron b of 'rubcarried by a transverse -bar 7J secured to theframe or otherwise. i

her or other suitable materialis providedflhe transverse apron b being advantageously to compensate "for variation inthe length of the belt, the transverse member above the a roller (i is connected to the longitudinal "inembersfb by means of web-plates j" carryin-g bolt-s which pass through longitudinally disposed slots 6 in the longitudinal member 6 The relative positionisdeterminedby means of abutments'or 'lugsb' on the longitudinal members I) and adjusting-'screws 9' I passing t'hroughscrewed bloc plate member -7 The forward movement and the transverse ste me t t reciprocation of the belts are elfeicted'from fa main driving shaft Z which is disposed" above and transversely to the tank a midway v i ers c of the two endless conveyors'may deliver between the two conveyors.

For the forward movement of the belts, there is provided on the main driving shaft Z a worm Z .which'engages aworm wheel Z ufixedlylmounted upon allo gitn nal shaft 13 by adjustment of the corresponding friction.

p ch are islid bly vl lcm te 't ic ion wheels Z adapted respectively to drive :fri'ction discs FL The latter are respectively mounted upon counter-shafts Z which carry pinions Z adapted toengage spur wheelse mounted fixedly upon-the shafts '6 of the upper roller :The' speed of the forward movement of each 'beltmay be readily varied and'regu'lated' wheel Z along-the transverse shaft Z- so that In order that the framemay-be adjusted be determined];

theispeedof rotation of the gcounterkshatt ,Z is increased or decreased. 7 v i For the transversereciprocation of the belts, .a shaft miscarried in-brackets m secured to one of the side walls of the tank at the .u'ppered'ge :on'lthe outer side, and so that thezshaft is disposed on the l velqof the plate member, 7' The shaft in is rotated from the'm'ain drivingshaft- Z by a friction wheel Z slidably-mounted'upon the main dri.v,

ing shaftl and engaging'a friction. disc m secured to the shaft m to be rotated so that the speed of rotation-.ofuthe latter-may be readi-ly varied. vOpposite each of the plate members j ithe shaft-m is fitted with an-eccen trio mt, therod'im of which is pivotally connected-to the adjacent end. of the, oppositely disposed plate member. The; connection is conveniently :made. byz meansio-f transverse axis or'pivot. pinm uponfthe.Qrond-m't en-a,

gaging a bearing bracket -j secured'tothe plate member 7' so that the pin mi isin the same horizontal plane as the shaft The bearing bracket 3' is conveniently formed with a channel-shaped :base or body portion, 1. which embraces and issecured to two-short.

lengths of. channelsection metal. vertically disposed one 'onieach sideiof the plate member j and secured thereto; In ,order' to avoid 3111- even movements and shockv and to makeup wear, a *lug on plate'm'ember; ij- -is conne'cted by a springm withla lug m fonthe adjacent "bearing 'bracket m q iz-l v thevsepar'ated material, 7 the tank is provided withqa'n inner chamber formed by a partition a wh-ichi extends par- For the collection-of alle'l to' one. of the side walls d of the tank and by end walls a a the upper portions of which are disposed at an' inclination corresponding in angle with'that of the adjacentend walls of the tank, while the qlowersportions ofthesaid walls are ,disposedvertically.

Thus, thelow'erportion of the chamber is' substantiall-y triangular in the transverse sec-,

tion and rectangular in the longitudinal sec-v tion. The upper open end of th'ejchamb'er extends in each'direction from themiddle of the tank sufiici'ent'ly to ensure that'thea pper rollthe heavier material theretoandthus, the heavier material prasse's downwardly through by any suitable means. An adjustable weir member a? may be provided'bywhich the level of water or other liquid within the tank may The coalorothermaterialcina finely divided condition is fed from a hopper n toitheupper part'of the inclined surfaceor tray 16 above the level of the liquidand, on the vibrationor transverse reciprocationof the inclined sur facelor tray b? andof'the' conveyor '12 the-finely:

- intothe position aflwhence it may be removed i arefed over the'upper edge ofthe end wall or :the battle 6 to 'accumulate'upon the-conveyor b at a position between the lower. end of divided material gradually passes downwardly and in doingso gradually separates, to a greater or less extent, the heavier from the lighterparticles, so that thehea'vier particles pass throughthe slot Z) in thetransversewall b of the baflle ontothe conveyor-b in P08111011;

immediately beneath, while the finer particles accumulate'at the bottomofthe'itray and the inclined surface or tray 6 and the' jointing apron I) referred to. In this way, the

particles are deposited on the conveyor b' more or less separated according -.totheir specific gravities, ithe coarser particles beingdeposited on the. conveyor in position above the finerparticles. Thus, in the upward movement of the .upper part of the. conveyor b, the respective particles are further separated and the1 finerparticlesaccumulate in a position between the lower end of the in- ,v clinedsurface or-atray 71 and the jointing napron 6 and pass over the upper edge ofthe 1 2'5' apron bf or its support c", into the liquid in If a position where iit is "separately: collected, 1 .while thefheavierparticles, pass upwardly on the conveyor b and are dischargedoverthe V pper-.endthe'reof into the liq-uid-andarethere collected.

a 'It'will. be understoodlthat the sur- 1 face or tray b is advantageously provided to .be transversely reciprocated withlthe con veyor b in the manner hereinbefore described.

iAccording'toiamodification, as illustrated in Figurea8, the-=coalor other-material in afinely divided condition may be fed from a supply hoppermor feed box to an inclined shoot '0, the lower end of which is immersed proximity of the supporting or upper sur-.

faceof-the beltvat a position whichis sufli- I ciently below the surface level of the water inthe water or other liquid and'reaehes-the or other liquid, that the material is delivered to the'belt at a' pointewhere the water or-otherQ liquid is undisturbed. The shoot, whichisf conveniently of a Widthsomewhat less than that of the, belt, may, as shown in the drawing,be carried by the roller frame so. that it partakes of the transverse reciprocation to. which the frame and the rollers are subj ectedr For thisjpurpose it maybe supported upon the longitudinal,members b by such meansas, brackets n?" to wh1ch1t is secured or upon which it is supported by boltsor pins? .in

.such; manner that the inclination may be variedas desired. V

The material delivered to'the endless belt 1 fromthe shoot is separated as the result of T the forward movement and transverse recip-' rocation of the belt! Thus, in the case of coal the heavy impurities are, deposited upon the belt surface. and remain thereon, being ear-,

Tied-upwardly and discharged over the. upper roller, while the coal as. the .result' of the latby means of acentrifugal pump."

eral reciprocation of the belt, is maintained in movement and passes downwardly for delivery over the'lower roller.

It is advantageous to provide transverse aprons or strips of rubber to bear upon the belt immediately over the lower rollers d and thus, toensure that the lighter substances accumulate against the apron and-finally disk posed bars or supports mounted on or sup=- portedfrom the side walls of the tank.

. When the material-to be separatedis of a o light character, such as jzinc slime,,t here is-a tendency for particles to float upon the sur- ,faceof the water or otherliquid. I It is desirable, therefore-that bafllevplates 19 should be disposedltransversely in the tank across the portion of: the tank abovethe lower endof the supporting or .upper surface ofrthe v belt. Certain of thebafiles-may be submerged in the water or other liquid withtheirqlower edges disposed at a distance of, for example, one quarter of an inch-from the supporting orupper surface of the belt, while the intermediate baffles may project above thelevel' of thewater or other liquid, andhave their lower edgesdisposed so that. they are lower than theupper edges of the submerged battles;

Thefloating particles connect against such bafilewplates and in time sink onto the belt. .-It isfurther desirable, with certain light materials,to,provide the shoot of closed form, or to fit over the lower end, which is,

immersed in the water or other or coversuch as n t V In the case of materials, such as zinc slimes, it is desirable to permit the separated constituents, more; particularly, the lighter constituent, to accumulate in the bottomof the tank and to pass, away merely by, overflowing liquid, a shield under the assistance ofascrew or paddle 7 elevator or agitator. 'It is further desirable:

to provide adraw-otf opening oroutlet for, the separatedconstituents at the lower end ofthe casing. This isspecially desirable in the treatment ofminerals giving heavy concentrates. The tailings may be pumped out It will furthermore be understood thatin addition to theinclined surface or tray aseries of bafiles 7 such as hereinbefore described my e mp y lelaim: 1 Y

1. Apparatus for the treatment of minerals rationcomprising an endless stratifying conand other substances for washing and sepaveyor whose upper surface is'inclined, a tank within which the said conveyor, is disposed,

the said tank being adapted to be filled with liquid to a level such that at least part of the said conveyor is immersed, means for reciprocating the said conveyor in a direction transverse to its upper surface, means for moving the upper surface of the said conveyor in an upward. direction, means for feeding to the said conveyor the finely divid ed and coarser particles of the substance to be treated at a position where it is adapted tobe immersed in the liquid contained in the tank and where the liquid is in a substantially undisturbed condition, comprising an inclined separating shoot having its lower part immersed in the liquid contained in the tank, the lower part having a transversely disposed end Wall at the end of the said inclined separating shoot adapted to serve as a weir and adapted for the discharge over it of a proportion of the finely divided particles, and an outlet near the front end of the said shoot adj acent the upper surface of the said shoot and adapted for the discharge of a substantial proportion of the coarser particles, and means for subjecting the said shoot to the same transverse reciprocation as the said conveyor, substantially as described.

2. Apparatus for the treatment of minerals and other substances for washing and separation comprising an. endless stratifying conveyor whose upper surface is inclined, a tank 7 within which the said conveyor is disposed,

the said tank being adapted to be filled with liquid to a level such that at least part of the said conveyor is immersed, means for reciprocating the said conveyor in a direction transverse to its upper surface, means for moving the upper surface of the saidconveyor in an upward direction, means for feed 7 ing to the said conveyor the finely divided and coarser particles of the substance to be treated at a position where it is adapted to be immersed in the liquid contained in the tank and where the liquid is in a substantially undisturbed condition, comprising an inclined separating shoot having its lower part immersed in the liquid contained in the tank, the lower part having a transversely disposed end Wall at the end of the said inclined separating shoot adapted to serve as a weir andadapted for the discharge over it of a proportion of the finely divided particles, an outlet near the front end of the said shoot adjacent the upper surface of the said shoot and adapted for the discharge of a substantial proportion of the coarser particles, means for subjecting the said shoot to the same transversereciprocaposed, the said tank being adapted to be filled with liquid to a level such that at least part of the said conveyor is immersed, means for reciprocating the said conveyor in a direction transverse to its upper surface, means for moving the upper surface of the said conveyor in an upward direction, means for feeding to the said conveyor the finely divided and coarser particles of the substance to be treated at a position where it is adapted to be immersed in the liquid contained in the tank and where the liquid is in a substantially undisturbed condition, comprising an inclined separating shoot having its lower part immersed in the liquid contained in the tank, the lower part having a transversely disposed end wall at the end of the said inclined separating shoot, adapted to serve as a weir and adapted for the discharge over it of a proportion of the finely divided particles, and an outlet near the front end of the said shoot adjacent the upper surface of the said shoot and adapted for the discharge of a substantial proportion of the coarser particles, means for subjecting the said shoot to the same transverse reciprocation as the said coveyor, the

to be disposed substantially parallel with the upper surface of the said conveyor, substantially as described. 7 v

THOMAS MALCOLM DAVIDSON.

tion as the said conveyor, and means for vary- I ing the inclination of the said inclined separating shoot, substantially as described.

3. Apparatus for the treatment of minerals and other substances for washing and separation comprising an endless stratifying conveyorwhose upper surface is inclined, a

tank within which the said conveyor is dis- 

